A new InGaP-GaAs double delta-doped heterojunction bipolar transistor (D/sup 3/HBT)

The double delta-doped heterojunction bipolar transistor (D/sup 3/HBT) is successfully fabricated with improved current-voltage characteristics by employing the insertion of delta-doped layers at the emitter-base (E-B) and base-collector (B-C) heterojunction. Due to the use of delta-doped layers, the potential spikes at the E-B and BC heterojunctions are suppressed substantially. Thus a higher emitter injection efficiency (current gain) and a lower knee voltage are obtained. From the experimental results, it is shown that the studied D/sup 3/HBT device is a good candidate for high-speed and high-power circuit applications.